what is back pressure?

Question

I have an '03 triumph speed triple and I want to show off the swing arm. I am currently running a TOR low mount exhaust and was wondering what the consequences would be if I simply took the can off. Actually, there is a piece of pipe that I will leave on (that connnects to the header-about 12inches in length) just beneath my foot, but I want to take off the entire carbon fiber bit. A good friend of mine who has/rebuilds old muscle cars says it shouldn't do anything to the bike or its performance. Another friend says he thinks it may be bad for the bike. Anyone know for sure?

Answer 1

Look, Back pressure is the pressure feed back to the engine. when an engine cylinder combusts fuel it is an explosion of sorts and the excess fuel gases or burn of is exhausted out.the muffler helps to reduce sound of this continues explosion but in modern mechanics helps with emissions by recirculating some of that unburned fuel gases to kinda help re burn them for engine efficiency.
So, If you remove it completely it will be louder and less efficient, meaning not burn as clean and use more fuel.Also you change the air to fuel set up by allowing the system to breathe more and the bike may run a little too lean and shorten its cylinder life because it will have more need for fuel with the better air flow and when lean the excess fuel washes more oil off of the cylinder walls shortening the life of the pistons and rings.
Instead of removing it, get a smaller sized aftermarket one with less baffled exhaust muffler and then have the carburetors synchronized to match the change.This way you can see the swing arm more with the smaller muffler and wont be effecting the run ability or life of the bike.

Answer 2

Most exhaust pipes do two things.
1) Modify the noise of the exhaust. This can be done to give an engine a sweet sound like a Porsch, Ducati, or Harley-Davidson but in most cases the exhaust just muffles the sound to make the engine quieter. Thus the term muffler. For the last 100 years this was ussually the only use of an exhaust ( and to keep the hot ar off the riders leg). This allowed riders to what you are attempting. This made thier bikes mre powerful and noisier. Two things many bikers wanted.
2) Change the perfrmance of the engine. As engines became more advanced the designers started to realize that the shape of the exhaust pipe also effected the performance of the engine. They discovered that the shape of the exhaust can modify the pressure that is felt by the exhaust gas trying to leave the cylinder. This is where people talk about back pressure. Ideally the exhaust pipe creates a situation that helps suck the exhaust gas out of the cylinder. Some manufacturers in recent years, like Yamaha and the EXUP system, have even gone so far as to dynamcally change the shape of the exhaust pipe at different RPM to get the most power out of the engine. If were to remove the back of an EXUP Yamaha exhaust your bike would would suffer in the performance category.

The big question: Is the '03 speed triple can just a noise reducer or is it a tuned exhaust? This is difficlt. On the triumph bikes that are retro (thunderbird) styled I think the cans are just noise reducers. On the new Triumph race bikes there is probably some tuning done so these would effect performance. The speed triple is in the middle so it could go either way.

My final advice: If the warranty is up take off the can and drive around. Your bike may look better, perform better, and sound better (even it it is illegally loud). On the other hand it may really kill performance. In this case you an sleep well knowing that your bike is state of the art and was designed by engineers who tuned the exhaust.

PS: There are also stories that engines with no exhaust at all (lacking both a header and can) can add extra heat to the exaust valve and even cook it This shouldn't be the case with a modern engine that still has a header.

Answer 3

Backpressure is the pressure present in the exhaust pipe while the bike is running due to the various restrictions in the exhaust. A small amount is actually good for a street bike as it can help fuel mileage a bit. Removing the muffler can may remove the backpressure altogether and it'll sure be louder. You may gain a bit of performance at the cost of lower gas mileage tho. I say MAY as you can also LOSE performance depending on the scavenging effect of open pipes on the intake charge. And you'll sure get the attention of the local law enforcement with the extra noise.

Answer 4

Removing the silencer will change the tuned length of the exhaust. This will result in changing the resonance, and in effect let the intake charge pass through the cylinder, with out being burned. This will of course hurt performance and efficency of the engine and raise the operating tempature and in turn burn your valves. sync'ing the t-bodies will not compensate for this change in length.

Answer 5

Back pressure is the resistance to flow of exhaust gas created by the exhaust system, and it results in a slight loss of power. The purpose of the exhaust system is to reduce noise and catch sparks; both of these are important, and a bike will probably not be street legal if the system is not in place and working.

Answer 6

I try properly below pressure, i'm no longer confident why. I type badly below pressure, my palms spazz out. I write properly below pressure, adrenaline, i wager. I learn computers badly below pressure. I even lost a job once because i did not %. it up quick adequate. So, i wager it relies upon on what i'm doing and how a lot stress is being utilized.

Answer 7

If you take it off the engine will run lean and can burn up the engine.

Answer 8

The valves tend to burn up quicker with less back pressure.